For years, clients have been asking Alex Talbot and Aki Kamozawa when they were going to open a restaurant. Little wonder. The couple’s blog, Ideas in Food, launched in 2004, is closely followed by the culinary vanguard for its freewheeling creativity and scientific sophistication in pursuit of maximum flavor. Indeed, Maximum Flavor: Recipes That Will Change the Way You Cook was the title of the second of three influential cookbooks that Alex and Aki, as they’re known, have produced.

The restaurant question also made sense because Talbot, 41, and Kamozawa, 43, are experienced chefs and high-priced consultants as well as husband and wife. “We finally opened a restaurant,” Talbot says with a laugh. “It’s just one that happens to serve only frozen custard and doughnuts.”

Curiosity Doughnuts, while not quite a restaurant, is a snug, smartly designed stall in the Stockton Market. It debuted October 2, and its deeply flavorful, ethereally textured doughnuts quickly drew OMGs from the fooderati. The stand, open only Saturdays and Sundays, often sells out. Talbot, the baker, hustles trays of hot doughnuts all day from the kitchen to the stand.

But why custard and doughnuts from the couple known for creations like lime-pickle pesto or liquid baked potato?

“I have a serious doughnut fetish,” Talbot admits. He traces it to his Westchester boyhood. Visiting East Hampton with his family, he stood in awe at the window of Dreesen’s Market, watching its famous doughnut machine fry classic cake doughnuts that he then wolfed down, hot and soulful. To this day, Talbot drags Kamozawa and their daughter, Amaya, 7, to check out old-school doughnut shops on their travels around the country.

But doughnuts were an afterthought when they visited the Stockton Market on Bridge Street last August and discovered that a stall was available. A maker of artisanal ice cream had recently departed, and market manager Dawn McBeth asked them if they do ice cream. “I said, ‘yes,’” Talbot relates, “‘but what I would do is soft-serve frozen custard.’ She asked, ‘What else would you do?’” His instant response: “Doughnuts!”

They started with the recipe they developed for Maximum Flavor. “It’s worth buying the book just for that recipe,” Talbot says. “But because I’m as stupid as I am, I thought we’d start from scratch, see what else we can do. We went through 15 versions. In the end, we applied what we learned to make the Maximum Flavor the best fricking doughnut ever. The goal is always to deliver greatness and deliciousness to people.”

It takes just one bite to realize that Alex and Aki have done just that. But one bite is never enough. Schnackenberg’s in Hoboken still makes peerless classic doughnuts, but as Talbot says, “ours aren’t classic. They’re something new.”

What’s new is the rich, moist texture under the crisp surface and the layers of deep flavor in the dough, glazes and fillings. Most Curiosity Doughnuts are made with a vanilla and buttermilk batter and are yeasted and fluffy. They come plain or in a variety of buttermilk glazes (vanilla, strawberry, butterscotch) and dustings (cinnamon-cardamom sugar, lime zest).

Some are filled—last fall, with their own homemade applesauce, followed by their own pumpkin pudding and vanilla pudding for the chocolate-covered Boston Cream doughnuts. Talbot fills them almost to bursting. “If you’re going to get it,” he says, “you’re going to get it.”

Talbot is particularly proud of their yeasted chocolate doughnut—a rarity, since most all-chocolate doughnuts are of the denser, unyeasted cake kind. “It was a challenge,” he says, “because you can’t pull out flour and sub cocoa as you do in a cake. But I’m very stubborn.”

The selection changes day to day, even hour to hour. One cake-style doughnut is wand-shaped and resembles Mexican churros. Around Thanksgiving, they introduced another called the New-Fashioned. “Most old-fashioned cake doughnuts are too crumbly and don’t have enough structure and body,” Talbot says. “So I started working with Japanese milk bread batter as a base, and I finally got it. It’s really good and really moist.”

The New-Fashioned has quickly caught on in various forms and flavors, now accounting for about 100 of the 700 to 800 doughnuts Alex and Aki sell a weekend. The Stockton Market is perfect for them—an eater’s paradise also featuring a superb pâtissier, chocolatier, artisan baker, Mexican street food, pizza, coffee bar, handmade preserves, imported olive oils, fresh vegetables, a seafood market and the More Than Q barbecue stand, with its perpetual line.

Every Wednesday, Talbot drives seven hours from their home in New Hampshire to Stockton to begin preparations. Kamozawa, Amaya and he stay with her family just across the river in Bucks County, Pennsylvania. They want to buy a home there, but to afford it, they first need to sell their New Hampshire home.

The name Curiosity Doughnuts was inspired by reading TV- and movie-producer Brian Grazer’s book, A Curious Mind, which trumpets the benefits of curiosity as an approach to daily life. “Our whole world is about curiosity,” says Talbot. Exhibit A is their blog.

“Most of our customers don’t know what Ideas in Food is,” Talbot admits. “I wish everyone in the world knew about it, because I think there’s something there. It’s still very cult-like. But they don’t need to know. The goal is delivering great doughnuts and frozen custard.”

The custard comes in just one flavor (vanilla buttermilk), “because we could only afford a single-flavor machine,” he says with a laugh. They designed it to pair with a doughnut of one’s choice in a sandwich called the Curiosity Doughnut, or in a sundae of custard, doughnut holes and toppings called the Freeze Brain.

“When you bring the custard and the doughnuts together,” Talbot says, “the result is heavenly.” You won’t find much argument at the Stockton Market, the only place the doughnuts and custard are sold.